Spectral Learning of Refinement HMMs Karl Stratos author Alexander Rush author Shay B Cohen author Michael Collins author 2013-08 text Proceedings of the Seventeenth Conference on Computational Natural Language Learning Julia Hockenmaier editor Sebastian Riedel editor Association for Computational Linguistics Sofia, Bulgaria conference publication stratos-etal-2013-spectral https://aclanthology.org/W13-3507/ 2013-08 56 64